The average cost of 7 textbooks is $50.
After a textbook that costs $80 is removed,
- What is new total cost of all the remaining textbooks?
- What is new average cost of all the remaining textbooks?
(a)
Total cost of 7 textbooks
= 7 x 50
= $350
New total cost of all the remaining textbooks
= 350 - 80
= $270
(b)
Number of remaining textbooks
= 7 - 1
= 6
New average cost of all the remaining textbooks
= 270 ÷ 6
= $45
Answer(s): (a) $270; (b) $45